It's no secret that during summertime, Baltimore has a crush on … crushes.

As the temperature starts to rise, so do the shipments of fresh oranges and grapefruits to bars and restaurants around town, especially those near and on the water.

Crushes — pint-glass cocktails typically made with flavored vodka, fruit juice and something sparkly, like Sprite or club soda — are Baltimore's unofficial drink of summer. They're also a bit of an anomaly. In a town that values tradition when it comes to favorite foods and drinks (think Natty Boh and crab cakes), crushes are a relatively recent phenomenon.

The first orange crush was made in 1995 at Harborside Bar & Grill, a waterside spot in West Ocean City.

"It's Smirnoff orange vodka and triple sec, one shot of each, fresh-squeezed orange juice from Florida or California oranges and topped with Sierra Mist," said Harborside bartender Phillip Lewis. The recipe, he said, has remained fairly consistent for years.

Steve Roop, the owner of Portside Tavern and Cask & Grain in Canton, became familiar with crushes at The Starboard in Dewey Beach, Del., where he worked between 1998 and 2006. He recalls that they started to "work their way" toward Baltimore around 2005. They weren't on the menu when Portside opened in 2004, he said, but they were added to the mix within its first year.

Roop gives credit to Patrick "Scunny" McCusker, the late owner of Nacho Mama's and Mama's on the Half Shell, for helping the crush expand beyond its beachy roots.

"I think he was the catalyst, the guy who brought the crush to Baltimore," Roop said.

"We started selling crushes 13 years ago," confirmed Scunny's widow, Jackie McCusker, noting that Mama's on the Half Shell's orange crush recipe has remained the same since the drink's introduction. "I don't think we thought we'd be blowing the roof off it like we do. But I'm proud we've never changed."

The first orange crush was made in 1995 at Harborside Bar & Grill in West Ocean City. About 10 years later, the drink migrated to Baltimore, where it has become the unofficial drink of summer. Now bars offer a variety of flavors, including grapefruit, and watermelon and basil.

Mama's isn't the only spot that has stuck with a traditional orange crush recipe. Roop said he's seen few changes at Portside as well.

"I think the only change over the years is that a lot of people are going for club soda versus Sprite, to make it a 'skinny crush,'" he said.

The bigger evolution in crushes is that on many menus, the "crush" category has grown far beyond orange. Grapefruit crushes, also made with fresh-squeezed fruit, have been hot for several years; other options include lemonade and mint julep-inspired bourbon crushes.

"I think classic crushes are great and delicious, but I like twists," said Laure Fraser, bar manager at Loch Bar in Harbor East. "For a while, we had a bourbon crush. It's a great way to make it a more popular drink — there's a different crush for everyone."

Hard Yacht Cafe in Dundalk sells a variety of crushes, including watermelon, lemon and pineapple. But orange, followed by grapefruit, remains the most popular, according to longtime bartender Courtney Cox.

With only a handful of ingredients, crushes sound like a simple drink, but they do invite some controversy — most notably, around the ice.

While some local bartenders insist the drink must be made with crushed or pellet ice, others are advocates for standard-issue ice cubes.

"We don't make them with crushed ice," said Roop. "Crushed is better for the bar or restaurant, but worse for the customer because it takes up more glass space. The ice doesn't offer any flavor either way."

Cox agrees with Roop. "Some people make crushes with crushed ice but I don't really like them that way because they get watered down too fast. We have solid cubes," she said.

Bartenders at Harborside also use "regular" ice. But those who champion crushed or pellet ice say the type of ice and the way it melts are critical elements of the drink.

At Mama's on the Half Shell, bartenders hand-crush the ice for drinks; at Loch Bar in Harbor East, the drinks are also made with crushed ice.

This summer, The Chasseur in Canton will open an open-air third-floor bar that will focus on crushes and oysters. Until then, however, the restaurant does not serve crushes because the downstairs bar does not have crushed ice.

"You have got to have the pellet ice," said general manager Natalie diFrancesco, explaining that the decision to add crushes to the new bar menu was linked with the need to buy a new ice machine.

"Because we're doing the raw bar, we had to get a second ice machine for the third floor," she said. "So it makes sense we're doing crushes."

Whatever their stance on ice type, bartenders agree that high-quality vodka and freshly squeezed juice are critical elements of a good crush.

"Fresh produce is key," said Roop. "Really good sun-kissed oranges and ruby red grapefruits when available. And use good alcohol, too."

"I think the ingredients are so important — it goes back to fresh-squeezed — but it's also about a great vibe," McCusker said. "Who's serving it. The people."

During the summer months — and even through the winter — crushes are enormously popular in and around Baltimore. Between May and August 2016, Mama's on the Half Shell sold 18,940 crushes; in all of 2016, they sold close to 57,000.

But for some reason, that popularity does not extend beyond the Mid-Atlantic region.

Mulligan's Raw Bar & Grille in Nags Head, N.C., is one of the few spots outside the Mid-Atlantic to offer crushes.

And even in the Outer Banks, crushes have Maryland roots.

Mulligan's owner, Gus Zinovis, drank his first crush in Maryland. "The first one I ever tried was in Ocean City at Seacrets," he recalled. "Then I started selling them down here at Mulligan's and we ended up being the orange crush location of the Outer Banks."

Zinovis said crushes have been available at Mulligan's for about seven years; today, they sell more crushes than any other drink during the summer months. "It's really the most refreshing summer drink," he said.

Bartenders acknowledge that keeping fresh fruit on hand is expensive and might be a deterrent to selling crushes, but otherwise, they aren't sure why the crush hasn't caught on outside the region.

Fraser says the servers at Loch Bar regularly chat with out-of-town guests about crushes. "Our servers talk about them and people love them," she said. "I think it's going to start slowly gaining in popularity as bartenders sell them to out-of-towners. It should be everywhere."